State profile · Above national median SD

Iowa bridge safety

Condition ratings, load ratings, and structural-deficiency data for every public highway bridge in Iowa — drawn straight from the FHWA National Bridge Inventory.

20,753
Public bridges
36.5%
Good condition
20.0%
Poor condition
20.0%
Structurally deficient

Total Bridges

20,753

Public highway bridges in Iowa

Good Condition

36.5%

7,582 bridges rated 7-9

-13.5pp vs 50% benchmark

Poor Condition

20.0%

4,153 bridges rated 0-4

Structurally Deficient

20.0%

4,153 bridges flagged for repair priority

13.0pp vs national avg 7.0%

Iowa vs national bridge condition

Iowa — Good condition share 36.5%
National avg

Share of bridges rated 7-9 on the FHWA 0-9 scale (deck, superstructure, substructure all good).

Iowa — Structurally deficient share 66.7%
National avg

Lower is better. Bar maxes at 30% (worst-state ceiling). National average sits at 7.0%.

Condition Distribution

Bridge inventory deck-condition mix — Iowa (FHWA NBI)

Iowa36.534476943092564%38.39444899532597%20.011564593070883%20.011564593070883%GoodFairPoorStructurally Deficient
Bridge inventory deck-condition mix — Iowa (FHWA NBI)

Counties (99)

Adair 208 Adams 147 Allamakee 170 Appanoose 159 Audubon 161 Benton 327 Black Hawk 411 Boone 119 Bremer 220 Buchanan 281 Buena Vista 140 Butler 261 Calhoun 171 Carroll 223 Cass 237 Cedar 265 Cerro Gordo 210 Cherokee 223 Chickasaw 268 Clarke 150 Clay 138 Clayton 214 Clinton 325 Crawford 242 Dallas 154 Davis 156 Decatur 178 Delaware 254 Des Moines 156 Dickinson 73 Dubuque 304 Emmet 70 Fayette 288 Floyd 195 Franklin 214 Fremont 133 Greene 150 Grundy 270 Guthrie 236 Hamilton 134 Hancock 128 Hardin 211 Harrison 162 Henry 144 Howard 193 Humboldt 70 Ida 164 Iowa 189 Jackson 209 Jasper 321 Jefferson 142 Johnson 317 Jones 215 Keokuk 152 Kossuth 256 Lee 185 Linn 428 Louisa 134 Lucas 186 Lyon 241 Madison 221 Mahaska 219 Marion 204 Marshall 283 Mills 170 Mitchell 160 Monona 125 Monroe 126 Montgomery 184 Muscatine 127 O'Brien 229 Osceola 176 Page 185 Palo Alto 114 Plymouth 407 Pocahontas 186 Polk 415 Pottawattamie 469 Poweshiek 221 Ringgold 206 Sac 188 Scott 212 Shelby 194 Sioux 429 Story 262 Tama 307 Taylor 220 Union 153 Van Buren 142 Wapello 160 Warren 231 Washington 203 Wayne 163 Webster 179 Winnebago 48 Winneshiek 317 Woodbury 379 Worth 89 Wright 168

Iowa vs nearby ranks

Adjacent states on the structurally deficient leaderboard (lower share = better)

States are ranked by share of bridges flagged structurally deficient — the FHWA classification for any span where deck, superstructure, or substructure carries a condition rating of 4 or below. Lower percentages indicate stronger maintenance funding and inspection follow-through. States here sit immediately above and below Iowa on the same metric.

54

West Virginia

16.02% top marginal rate
Structure
Progressive
Burden @ $100K
$7,679

46

South Dakota

16.24% top marginal rate
Structure
Progressive
Burden @ $100K
$5,905
Selected

19

Iowa

20.01% top marginal rate
Structure
Progressive
Burden @ $100K
$20,753

78

Virgin Islands

29.17% top marginal rate
Structure
Progressive
Burden @ $100K
$24

Bridges Needing Most Attention in Iowa

Six lowest-condition bridges in Iowa, ranked by composite NBI rating. Each is inspected at least every 24 months.

270TH STREET

Structurally Deficient

Over: ROSE BRANCH

071343401, Adams, IA

Built 1976 Load: 2.7 t ADT: 79

LOCAL

Poor

Over: CREEK

078342601, Audubon, IA

Built 1935 Load: 2.7 t ADT: 21

KLINE RD

Structurally Deficient

Over: MUD CREEK

87-12-15-02-10, Black Hawk, IA

Built 1948 Load: 2.7 t ADT: 11

LOCAL - 700TH

Structurally Deficient

Over: TRIB TROUBLESOME CREEK

077351402, Cass, IA

Built 1983 Load: 2.7 t ADT: 11

LOCAL - DAYTONA

Structurally Deficient

Over: BUCK CREEK

077361903, Cass, IA

Built 1980 Load: 2.7 t ADT: 35

100TH ST.

Structurally Deficient

Over: UNION CREEK

083E20101, Clinton, IA

Built 1900 Load: 2.7 t ADT: 78

All Bridges in Iowa

190TH ST

Good

Over: SMALL STREAM

072312301, Union, IA

Built 2013 Load: 38.9 t ADT: 339

215TH AVE

Good

Over: BRANCH DES MOINES RIVER

072152704, Wapello, IA

Built 2022 Load: 38.9 t ADT: 70

SW 9TH STREET

Good

Over: MIDDLE CREEK

077240904, Warren, IA

Built 2023 Load: 38.9 t ADT: 4,465

FM

Good

Over: BOB WHITE ST. PARK

068220901, Wayne, IA

Built 2010 Load: 38.9 t ADT: 230

FM

Good

Over: UPPER IOWA RIVER

099091005, Winneshiek, IA

Built 1999 Load: 38.9 t ADT: 206

D 30 (180TH ST)

Good

Over: CREEK

088471301, Woodbury, IA

Built 2011 Load: 38.9 t ADT: 159

L 14 (KNOX AVE)

Good

Over: WOLF CREEK

0894329, Woodbury, IA

Built 2012 Load: 38.9 t ADT: 60

D2 110TH ST

Good

Over: CREEK

089431203, Woodbury, IA

Built 2020 Load: 38.9 t ADT: 409

R35 KEOKUK AVE

Good

Over: EAGLE CREEK-D D 36

093253502, Wright, IA

Built 2017 Load: 38.9 t ADT: 50

JENNINGS DR

Good

Over: DRY RUN CREEK (UNI)

0.3 mi. S of Univ. Ave., Black Hawk, IA

Built 1978 Load: 39.0 t

LOCAL

Good

Over: BEAVER CREEK

083282801, Boone, IA

Built 1999 Load: 39.0 t ADT: 15

HAWTHORNE AV

Good

Over: STREAM

092132902, Bremer, IA

Built 2002 Load: 39.0 t ADT: 29

LOCAL

Good

Over: RACCOON RIVER

090361301, Buena Vista, IA

Built 1992 Load: 39.0 t ADT: 71

US 59

Good

Over: GREY CREEK

0.7 mi. S of Jct. SR C16, Cherokee, IA

Built 1985 Load: 39.0 t ADT: 2,000

190TH ST.

Good

Over: DRAINAGE DITCH #11

082E12301, Clinton, IA

Built 1976 Load: 39.0 t ADT: 47

230TH AVE

Good

Over: NEGRO CREEK

082E32902, Clinton, IA

Built 1987 Load: 39.0 t ADT: 360

170TH ST.

Good

Over: BROPHY CREEK

082E50901, Clinton, IA

Built 1971 Load: 39.0 t ADT: 70

LOCAL 230 ST

Good

Over: PLUM CREEK

088030701, Delaware, IA

Built 1991 Load: 39.0 t ADT: 50

JEFFERSON RD

Good

Over: SMALL STREAM

088051004, Delaware, IA

Built 2003 Load: 39.0 t ADT: 1,719

LOCAL 280 AVE

Good

Over: PLUM CREEK

089033002, Delaware, IA

Built 1989 Load: 39.0 t ADT: 39

LOCAL BUCH-DEL

Good

Over: S FORK MAQUOKETA RIVER

090061902, Delaware, IA

Built 1997 Load: 39.0 t ADT: 59

OTTER RD

Good

Over: LITTLE TURKEY RIVER

095093410, Fayette, IA

Built 1991 Load: 39.0 t ADT: 29

LOCAL

Good

Over: FLOOD CREEK

095172601, Floyd, IA

Built 2004 Load: 39.0 t ADT: 33

US 18 WB

Good

Over: IA NORTHERN RR & STREAM

1.1 mi. E of Jct SR S70, Floyd, IA

Built 1998 Load: 39.0 t ADT: 5,350

LOCAL

Good

Over: BR BEAVER CREEK

088170604, Grundy, IA

Built 2001 Load: 39.0 t ADT: 97

DOUGLAS AVE

Good

Over: LITTLE WAPSIPINICON

098141504, Howard, IA

Built 2020 Load: 39.0 t ADT: 69

FM

Good

Over: SMALL STREAM

081211201, Jasper, IA

Built 2001 Load: 39.0 t ADT: 80

LOCAL

Good

Over: STREAM

074212703, Marion, IA

Built 2005 Load: 39.0 t ADT: 30

IA 330 SB

Good

Over: NORTH SKUNK RIVER

0.9 MI N OF N JCT SR S52, Marshall, IA

Built 2002 Load: 39.0 t ADT: 4,150

REDWOOD AVE

Good

Over: DUTCH BRANCH

078381602, Shelby, IA

Built 2014 Load: 39.0 t ADT: 51

FM RD F32

Good

Over: LONG BRANCH

802137, Shelby, IA

Built 1999 Load: 39.0 t ADT: 29

FM

Good

Over: EAST 102 RIVER

068330401, Taylor, IA

Built 1984 Load: 39.0 t ADT: 29

FM

Good

Over: SOUTH AVERY CREEK

072152105, Wapello, IA

Built 2004 Load: 39.0 t ADT: 330

FM

Good

Over: BRUSHSY CREEK

088271606, Webster, IA

Built 2004 Load: 39.0 t ADT: 748

GYPSUM HOLLOW RD

Good

Over: CC RR

089283304, Webster, IA

Built 2005 Load: 39.0 t ADT: 2,384

FM

Good

Over: NORTH LIZARD CREEK

089291504, Webster, IA

Built 1997 Load: 39.0 t ADT: 549

FM

Good

Over: SMALL CREEK

097073606, Winneshiek, IA

Built 2005 Load: 39.0 t ADT: 79

420TH AVE.

Good

Over: MILL CREEK

082E61602, Clinton, IA

Built 2021 Load: 39.1 t ADT: 166

LOCAL

Good

Over: BR OF WHITE BREAST CR

073222303, Lucas, IA

Built 2009 Load: 39.1 t ADT: 26

FM C-70

Good

Over: ELLIOT CREEK

090453501, Plymouth, IA

Built 1999 Load: 39.1 t ADT: 450

IA 1

Good

Over: LONG CREEK

1.0 mi. N of Jct. SR G36, Washington, IA

Built 1987 Load: 39.1 t ADT: 4,100

N FOLK HOLLOW RD

Good

Over: NORFOLK CREEK

097051904, Allamakee, IA

Built 2017 Load: 39.2 t ADT: 118

US 30

Good

Over: UNNAMED STREAM

4.8 mi. E US30/IA1INTCHG, Cedar, IA

Built 2019 Load: 39.2 t ADT: 5,500

S18 EAGLE AVE

Good

Over: WILLOW CREEK

097223504, Cerro Gordo, IA

Built 2019 Load: 39.2 t ADT: 727

310TH ST

Good

Over: LITTLE SIOUX RIVER

097372802, Clay, IA

Built 1986 Load: 39.2 t ADT: 81

AZTEC RD

Good

Over: STREAM

093061904, Clayton, IA

Built 2020 Load: 39.2 t ADT: 35

GRAND AVE

Good

Over: ROLLING HILLS CREEK

.5 Mi. W. of S JC Pkwy, Dallas, IA

Built 2019 Load: 39.2 t ADT: 96

EB IA 141

Good

Over: BEAVER CREEK

1.3 MI. E OF JCT. US 169, Dallas, IA

Built 1997 Load: 39.2 t ADT: 4,300

RHOMBERG AVE

Good

Over: BEE BRANCH

N OF KNEIST ST, Dubuque, IA

Built 2017 Load: 39.2 t ADT: 4,648

IA 150

Good

Over: OVER ABAND RR

0.5 mi. S of Jct. IA 93, Fayette, IA

Built 1961 Load: 39.2 t ADT: 2,700

Showing 13,951-14,000 of 20,753 bridges

Related

All states → | National rankings → | Understanding conditions → | SD bridges explained →
Data sourced from the FHWA National Bridge Inventory (NBI), latest released cycle. See our methodology for details. Retrieved and formatted by PlainBridges Editorial.

Disclaimer: This information is provided for informational purposes only and does not constitute professional advice. Data is sourced from the FHWA National Bridge Inventory (NBI). A "structurally deficient" rating is a repair-priority signal, not a closure or unsafe-to-cross designation. Consult a qualified civil engineer before making decisions based on this data.

Understanding Bridge Conditions

How FHWA rates bridge condition on a 0-9 scale.

Check Your Daily Bridges

How to look up bridge condition data for bridges on your route.

Read our methodology — how this data is sourced, computed, and verified.